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Discussion Starter #1
OK so I have the ZZ4 installed in my 77 but sure wish i would have just went with the hot cam when we did the swap....

my question is.. what else do i need to do the swap.. i read all i need is the cam and lifters.. i found the cam for 100 new and was thinking i could just get the lifters and save a little..

only have 5 k on new motor..

thoughts..
 

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If your existing springs can handle the new cam specs. The cam and lifters and a few new gaskets is all you need. You can change the cam with the motor in the car.

You only need to take out about the front half of the oil pan bolts to get the timing cover off. Use the sealant call "The right Stuff" to put it back together
 

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If the engine is in the car when you swap cams you'll need to take the radiator and condenser out as well. There isn't enough room to pull the cam with the radiator in place.

That being said, new cam, matching springs, gaskets, and tune.
 

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All you need is the cam,lifters and 1.6 self eln. rockers.
You already have the correct springs you should look into getting some hardened push rods and a Edl performer rpm.
There is a couple of places out there that claim they picked up some hp with the hardened push rods.
The guys at the old Sally chevy say the edl performer rpm can help you pick up some more hp to.
 

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Discussion Starter #5
Sounds like a mixed bag of info.. some people say all you need is the lifters, then others say all you need is the rockers.. ? ?
THis is a new zz4 with under 6kmiles ..I just wish i would have dont this while the motor was out of the car.,.
 

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Sounds like a mixed bag of info.. some people say all you need is the lifters, then others say all you need is the rockers.. ? ?
THis is a new zz4 with under 6kmiles ..I just wish i would have dont this while the motor was out of the car.,.

The ZZ4 comes with 1.5 rockers. Yes, 1.6 can add a bit of top end HP but not much. It won't hurt but you don't have to do it.

The springs are the most important part of the swap. Your ZZ4 springs might be within range of what the Hotcam requires but it's a better practice to buy the cam and springs in a kit. They are matched and need to be as close as possible.

Gaskets obviously are needed when you're opening up the top end.

As far as push rods, I think using the ones in the ZZ4 are fine. The heads should have self aligning rockers and no guide plates. However, if you do have guide plates, or switch to using them with non self aligning rockers, you'll need hardened push rods.
 

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Isn't the ZZ4 roller cam to start with? If it's roller you shouldn't need to replace the lifters.

Anybody picking up horsepower with hardened pushrods is actually picking up power from different valve adjustment than the previous pushrods had. As noted, hardened has to do with whether the pushrod or rocker is what's doing the alignment. Either way, you need a quality pushrod with spheres welded to the ends, not a rod that's had the ends press-formed into a round shape.

I'd change the springs too. And the rocker ratio is not what would concern me, it's rocker construction. The hot cam is gonna stress a stock type rocker pretty hard and I'd want a quality full bearing roller rocker. After working for a manufacturer that made many aftermarket rockers, comp cams magnum is the class of the field in terms of material and quality standards.

good luck!
 

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We have just about the same setup. I've been studying power enhancement for my car in all forms for a couple of years. The consistent answer (I've found) for the hot cam swap is cam and rocker arms anything else is nice to have.
I'm a little surprised at the ET, HP & Tq on your car. I can't help but think that there's something beside the engine holding back some power. Did you go through the exercise of jetting and cam-ing the carb? What really held mine back initially was the ram's horn exhaust manifold. There was a measurable improvement when I put the block huggers on.
Been on the fence with the cam swap, still trying to decide exactly what I want to do ie, save gas, street/strip or modified ET, and what kind of times to run.
Please keep posting, I'm interested in how it turns out.
 

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I have the HOT cam in my 78. 1998 5.7 truck engine-ported & polished vortec heads (read Dave Vizard's book and bought a grinder...) Comp Cams magnum rocker arms, performer intake, 800 CFM Q-Jet. The TH350 lasted less than 3 full throttle upshifts, so I switched to a M-20 4 speed. I really enjoy the combo since I installed the long tube headers-I had the rams horn, kinda felt a bit stifled, did run well though. I have been working on getting the jetting just right. I have opened up the idle tubes slightly, finally moved up to an 80 jet, 50k rods, CE secondary rods. The combo still seems a little lean at cruise. Very docile at low rpms, comes on at 3000 and pulls to 6500. Cammy if the idle rpm set to 650-700, fairly smooth when idle stepped up to 800 rpm or so.
I recall the ZZ4 has a roller cam in it so the lifters will work ok. Check the springs-if you dont have the correct pressures or clearances, you will break things quickly. Make NO assumptions. ( I learned the $$$ way in my youth)
If you are running an automatic-get a loose convertor-I'd think a 2500 stall would work well. I had the stock convertor in mine and it was a slug untill the rpms came up. Since I installed the 4 speed and headers I have run a C-6 manual in a little street race and stood right with him to 75. I think if the race had gone farther I would be looking at his taillights, but I was happy with the results so far. :thumbsup:

The answer to your questions: You will need a cam, gaskets and possibly valve spriing shims (to correct closing pressures). If you go up to the 1.6 rockers-double check the spring stack when open: ZZ4 cam has a max lift of .510 exhaust-HOT w/1.6 will be .525.
 

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I have done the lt4 hot cam swap in my zz4 I researced it endlessly I talked to GM PP and the guys at Sally chevy before they went under and lots of other places.
The springs in the zz4 heads are the same ones that come in the lt4 hot cam kit.
You need the cam and the 1.6 self alighning rockers to get the .525 lift.
The new lifters are not nessissary if you dont mind using your used lifters.
The EDl. performer rpm and hardened push rods are optional they are just things that are supose to help with HP.
The idea behind the hardened push rods is that the stock zz4 push rods deflect and you dont get full lift its in an article in one of the online magizines Hot rod or super chevy I cant remenber which one.
 

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Discussion Starter #12
I Have had my QJ re jetted and the dist has been curved...When I dynoed it was 250. im sure im off a good 20 hp.. im going to go with an elec fan set up so ill get a little there and a different pulley set up.. id like to see 300-325 and im good..


We have just about the same setup. I've been studying power enhancement for my car in all forms for a couple of years. The consistent answer (I've found) for the hot cam swap is cam and rocker arms anything else is nice to have.
I'm a little surprised at the ET, HP & Tq on your car. I can't help but think that there's something beside the engine holding back some power. Did you go through the exercise of jetting and cam-ing the carb? What really held mine back initially was the ram's horn exhaust manifold. There was a measurable improvement when I put the block huggers on.
Been on the fence with the cam swap, still trying to decide exactly what I want to do ie, save gas, street/strip or modified ET, and what kind of times to run.
Please keep posting, I'm interested in how it turns out.
 

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Discussion Starter #13
YEah Im still running my stock trans and converter.. its all been rebuilt with a shift kit but its still a 3 speed..
im working on getting an od trans down the road with new gears..355 373 ? ?


I have the HOT cam in my 78. 1998 5.7 truck engine-ported & polished vortec heads (read Dave Vizard's book and bought a grinder...) Comp Cams magnum rocker arms, performer intake, 800 CFM Q-Jet. The TH350 lasted less than 3 full throttle upshifts, so I switched to a M-20 4 speed. I really enjoy the combo since I installed the long tube headers-I had the rams horn, kinda felt a bit stifled, did run well though. I have been working on getting the jetting just right. I have opened up the idle tubes slightly, finally moved up to an 80 jet, 50k rods, CE secondary rods. The combo still seems a little lean at cruise. Very docile at low rpms, comes on at 3000 and pulls to 6500. Cammy if the idle rpm set to 650-700, fairly smooth when idle stepped up to 800 rpm or so.
I recall the ZZ4 has a roller cam in it so the lifters will work ok. Check the springs-if you dont have the correct pressures or clearances, you will break things quickly. Make NO assumptions. ( I learned the $$$ way in my youth)
If you are running an automatic-get a loose convertor-I'd think a 2500 stall would work well. I had the stock convertor in mine and it was a slug untill the rpms came up. Since I installed the 4 speed and headers I have run a C-6 manual in a little street race and stood right with him to 75. I think if the race had gone farther I would be looking at his taillights, but I was happy with the results so far. :thumbsup:

The answer to your questions: You will need a cam, gaskets and possibly valve spriing shims (to correct closing pressures). If you go up to the 1.6 rockers-double check the spring stack when open: ZZ4 cam has a max lift of .510 exhaust-HOT w/1.6 will be .525.
 

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YEah Im still running my stock trans and converter.. its all been rebuilt with a shift kit but its still a 3 speed..
im working on getting an od trans down the road with new gears..355 373 ? ?
Nothing wrong with the 3 speed. The OD will help a little with fuel mileage, but you have to drive alot of miles to get your $$ back.
 

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Discussion Starter #15
Nothing wrong with the 3 speed. The OD will help a little with fuel mileage, but you have to drive alot of miles to get your $$ back.
I do a lot of weekend cruising ... in 2.5 yrs i have close to 25k miles ..... Im going to wanna change gears to when i do the trans.......
 

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Discussion Starter #17

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Discussion Starter #18
OK so does anyone know how i can tell if I for sure have the correct cam.. ??? I purchased it from Craigslist..LOL I know..
I has the correct part # on the tube.. but can i make sure on the cam stamp some how.. ? ?
 
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